Process for the production of colored masks in photographic color material



United States Patent PROCESS FOR THE PRODUCTION OF COLGRED MASKS IN PHGTGGRAPHIC COLOR MATERIAL Heinz Berger, Leverknsen-Bayerwerk, and Edith Weyde, Leverirusen-Wiesdorf, Germany, assignors to Agfa Aktiengeselischaft fiir Photofabrikation, Leverkusen, Germany, a corporation of Germany No Drawing. Application October 19, 1949, Serial No. 122,364

Claims priority, application Switzerland Uctober 22, 1948 7 Claims. (Cl. 952) This invention relates to color photography and to methods of producing color photographs of the kind which are associated with masking images.

The use of masks in the production of color prints or transparencies from color negatives is Well known. These masks are to compensate for the deficiencies in the absorption of the color, pigments or inks, especially of the magenta and cyan dyes used in these materials. According to these known methods the masking images are produced either on separate photographic materials or within the color negative material itself. The former method is rather complicated, as additional film and additional printing operations as well as special methods for proper registration of negative and mask are necessary. The latter methods display the disadvantage that they require rather complicated processing steps.

It has now. been found that masks can be produced within the original film according to a, very simple process. This is performed in such amanner that a photographic material containing light-sensitive silver salts, color couplers, and nuclei for development is exposed to light reflected from acolored object and is color developed in a special developer. During the development process the exposed silver salts are. developed to give a color image, whereas the residual unexposed silver salts are dissolved and developed in contact with said nuclei for development to give a coloredmask for said color image.

There are several possibilities for performing this process.. One. possibility is based on the disclosure of the Norwegian Patent No. 66,994, patented January 24, 1942, or the French Patent No. 879,995, patented March 5, 1942. In these patents the production of black and white positives from positive originals by way of' an additional layer has been described. This additional layer is in direct contact with the. light-sensitive emulsion layer and does. not: contain a light-sensitive substance but nuclei for development, such as colloidal noble metals, for instance, colloidal silver, gold, etc., or noble metal compounds that are difiicultlysoluble in water, for instance, silver. sulfide. By using; a special developer which. be-

sides the usual developing substances, such as metol and hydroquinone, also contains silver halide solvents, the non-exposed residual silver halide dissolves duringv the development of the exposed silver halide and diflfuses into the adjacent layercontaining the nuclei for development where it is reducedto silver by the catalytic action of said nuclei to a positiveimage of the. original. The foregoing process for the direct production of black and white positives from positive originals is now applied accordingto the presentinvention to the production of masking images in a color photographic process. Proc essing can be carried out, for instance, in such a manner that one or more color components are added to the yellow filter layer which is produced in a. multi-layer photographic material according to the. orthodox, layer arrangement, provided that the yellow filter consists of colloidal silver. Otherwise, nuclei for development, for instance, in the form of colloidal silver must first be added to the yellow filter layer. If such color photographic material is exposed and subsequently developed in an ordinary color forming developer, i. e. a developer containing, for instance, para-phenylene diamine or its derivatives, no masking image is obtained, but a color negative or positive respectively only is. produced in. the

"ice

usual manner. If, however, also silver halide solvents are added to the color forming developer, the residual silver halide dissolves and diffuses towards the yellow filter layer where it is reduced to silver, the oxidation products of the color developer coupling with the color couplers present in the yellow filter layer, whereby a dyestuif is formed. A colored masking image is thus obtained, which has a reverse gradation to that of the photographic record in the emulsion layer or layers, the said characteristic being in conformity with the theoretical demands. As silver halide solvent, for instance, sodium thiosulfate, potassium thiocyanate, sodium sulfite, etc. may be employed.

On proceeding according to the present invention, for instance, the following arrangement of layers may be used. Upon the support is a gelatin layer containing only nuclei for development and one coupling component necessary for masking the blue green dyestuif image. Upon this layer the red-sensitive layer with a color coupler for the blue-green dyestufi image is applied. Thereupon, as usual, is a green-sensitive layer with a color coupler for the purple dyestulf image Thereupon the yellow filter layer is applied, which contains the nuclei for development and one or more color components for masking the purple and perhaps also the yellow layer. Upon the yellow filter layer is the upper layer, viz. the blue-sensitive layer with the color coupler for theyellow dyestufi image. However, it is quitepossible to modify the layer arrangement as well as. the arrangement or number of the masking layers and the color components in said masking layers; On developing the aforesaid materials an undesired fog, the so-called contact fog, is formed at the places of contact of the gelatinlayers which contain nuclei for development and the light-sensitive silver halide layers. In order to prevent the formation of this contactyfog, it is feasible to separate the lightsensitive silver halide layers from these gelatin layers by a thin intermediate gelatin coating.

Example 1 A negative emulsion sensitized for the red portion of the spectrum and containing per kilogram 20 grams of the following color coupler for a cyan dyestufi which is fast to diffusion is applied to any support desired:

CHBIF- 0111- Upon this coating a layer of 6% gelatin solution is applied to which per kilogramv 0.3 gram of colloidal silver has been added. Furthermore, this layer contains an addition of the following color coupler:

COOH

and containing an addition of 20 gramsof the following component:

is applied which on chromogenic development gives a CODE 1 11350110 own-Q 0.01120 O.NH

( OOH After exposure this material is developed in a developer of the following composition:

2.75 grams of p-diethylamino aniline hydrochloride 75 grams of potassium carbonate 0.5 gram of potassium bromide 30 grams of sodium sulfite of 2 grams of sodium thiosulfate, cryst 1000 cos. of water On developing the following reaction takes place. A negative image consisting of silver and dyestuff is formed in the emulsion layers in the usual manner. Silver halide saltsin quantities inversely proportional to the developed negative images in the emulsion layers-diffuse from the emulsion layers sensitized for the green and red portions of the spectrum into the layer containing colloidal silver. The silver salts are reduced by the developer in the presence of colloidal silver; at the same time, coupling of the color component added to the layer with the oxidized color developer takes place, a yellow color mask being obtained thereby.

Example 2 The arrangement of layers of the material is the same as in Example 1, the gelatin layer, however, besides colloidal silver, contains an addition of 6 grams of a color component which is fast to diffusion for chromogenic development of the following constitution:

COOH

I HasCmCQNH-OC oomcoma-Q 4 grams of a color component which is fast to diffusion for chromogenic development of the following constitution:

4 grams of a color component which is fast to dilfusion for chromogenic development of the following constitution:

CHaN. 011E315 After exposing, developing, bleaching and fixing in the developer as described in Example 1, a masking image of approximately grey color is obtained in the gelatin layer.

Example 3 A multi-layer material is used the emulsion layers of which have the same arrangement and the same composition as in Example 1. The gelatin layer betwee'rl the red and green sensitized emulsion layers, however, is dispensed with, and, instead of it, to the filter layer of colloidal silver between the green sensitized and the nonsensitized emulsion layer there are added 6 grams of a color coupler of the following constitution:

COOH

After exposing, developing, bleaching and fixing, a yellow masking image is obtained in the filter layer.

Example 4 The emulsion layers of the multi-layer material have the same arrangement and composition as in Example 1. Between the support and the emulsion layer sensitized to the red portion of the spectrum a gelatin layer is applied, which contains the same color components which are fast to diffusion for the chromogenic development as the red sensitized layer. Furthermore, between the green and red sensitized emulsion layers is applied a gelatin layer with an addition of the same color component for a yellow color image as is contained in the non-sensitized layer. After exposing, developing, bleaching and fixing, a cyan and a yellow masking image respectively is obtained in the gelatin layers.

We prefer to modify this process for the production of masks in color photographic materials according to the method for the direct development of positives as described in the copending application Serial No. 109,073, filed August 6, 1949, by Edith Deyde. It can be carried out, for instance, according to the following two methods:

At first details are given regarding the first processing method, and a material is referred to containing color couplers for the chromogenic development, which are fast to dilfusion. It is known that silver chloride emulsions are blackened also without exposure by photographic developers which are free of potassium bromide and have a certain dissolving power for silver chloride. This reaction is accelerated by the addition of nuclei for development, such as colloidal silver, colloidal gold, silver sulfide, etc. If a layer consisting of a mixture of silver chloride emulsions and higher sensitive silver bromide emulsions is exposed to light from an object in such a way that only the silver bromide emulsion is affected, and the layer is developed with a chromogenic developer which is practically free from potassium bromide and wherein silver chloride is more easily soluble than silver bromide, the silver bromide emulsion is developed to a negative image of the original, while the potassium bromide formed thereby prevents the reduction of the dissolved silver chloride which, therefore, is reduced to a positive silver image at the non-exposed places only. This process is not limited to silver chloride and silver bromide emulsions but can quite generally be carried out with mixtures of silver salt emulsions of different sensitivity and with developers exhibiting a higher dissolving power as to the less sensitive portion of the silver salt emulsions and containing no salts whose anions are the same as those of the more sensitive silver salts. The proportion of the more sensitive components of the silver salt emulsions in the above layers amounts to at least 5% of the whole mixture. After bleaching and fixing the above material, a negative color image and masking image of the same color is left in the layer. The layers formed according to the above process may find application in multi-layer materials either for one or for several layers containing color components. If some of these layers are sensitized, the sensitizer is added only to the more sensitive portion of the silver salt emulsions, while the color components are added in quantities of about 10 to 25 grams/ kilogram of the emulsion mixture. The emulsion layers of such materials can be separated from each other by thin intermediate layers of gelatin.

The second method is based on a special emulsion layer for the production of masks. This masking layer also consists of a mixture of differently sensitive silver halide emulsions with an addition of nuclei for development,

developer described in the lioregoing paragraph. After bleaching and fixing, :a negative color image of the object is obtained in the image layer, and a positive color masking image :as well as a very weak negative color image of the original is obtained in the masking layer. If in the masking ilayer and in the image layer adjoine'd thereto the same couplers are used, the weak negative color image obtained in the masking image is not troublesome but may even often be of advantage, if a certain partial color image in a mu'lt'i-layer material is to 'be intensified. Sometimes, however, :it may be :desired to prevent the formation of this negative color image in the masking layer. This object can be achieved by adding small amounts of non-chromogenic developing substances of higher reducing power than that of the chromogenic developer, for instance, metal, to the chromogenio developer. In that case, reduction of the higher sensitive portion of the emulsion mixture in masking layer is effected by this substance without any color formation, as these developers :give no developmentproduets capable of coupling. Qn the other hand, the much larger amounts of silver chloride are reduced mainly by the color developer whose oxidation products together with the color couplers give the desired dyestuffs. In multilayer materials one or more of these masking layers maybe applied at any place desired, for-example, as coating between the support and the lowest partial color layer, as intermediate coating between the partial color layers or as coating upon the upper partial color layer. These masking layers may contain the same color couplers as the image layers adjoined thereto; however, they may also be dififerent from those of the image layers, and also mixtures of different couplers may be used in the same masking layer. The masking layers can be separated from the image layers by thin gelatin layers.

The following examples further illustrate the invention without restricting it thereto:

Example 5 A negative emulsion sensitized for the red portion of the spectrum and containing per kilogram of emulsion 20 grams of a color coupler for a cyan dyestutf, which is fast to dilfusion and corresponds to the following constitution:

HaC.N.C 7Ha5 OH NH.CO

per liter of emulsion and 10 grams each of the color components corresponding to the following constitutions:

COOH

HtsCmC own-Q0 O.CH2.O ONE-O NH.CO.CH2.CHCisHa7 O OH (50.0HLCN Upon this masking layer is applied a green-sensitive negative emulsion containing per liter grams of a color B coupler'ffora magenta dyestufi of the following constitution z' I After exposure this material is developed at 18 C. in a developer of the following compos1tion:

Water ccs 1000 p-Diethylamino aniline hydrochloride grams 3 p-Monomethylamino phenol sulfate do 0.05 Sodium sulfite sicc do 3 Potassium carbonate do.. 20

After bleaching and fixing, the partial color images are left in the emulsion layers, and a mask of yellow-orange color is left in the masking layer.

We claim:

1. A light sensitive material for producing masked color photographic images which comprises (a) at least one light sensitive silver halide emulsion layer containing a color coupler which couples with the oxidation product of a primary aromatic amino developing agent upon photographic devolpment to give a colored image and (b) a masking layer containing a spontaneously developable silver salt emulsion which is developable in a special photographic developing solution without exposure to actinic light and from about 1% to about 10% of the whole mixture of a light sensitive silver salt emulsion which is developable in said special developing solution only after exposure to actinic light, said spontaneously developable silver salt emulsion being of such lower light sensitivity than said light sensitive silver salt emulsion that upon exposure to the object to be reproduced only said light sensitive silver salt is aifected, said special developer being a solution of a primary aromatic amino developing agent containing a solvent agent for said spontaneously developable silver salt and containing salts having the same anions as those of said light sensitive silver salt at most in such a quantity that the reduction of said spontaneously developable silver salt emulsion is not prevented, said masking layer containing furthermore a color coupler as defined above and reduction nuclei said reduction nuclei being capable of catalysing the reduction of a silver salt emulsion to silver by a photographic developing solution without exposing said emulsions containing said reduction nuclei to actinic light.

2. A light sensitive material as claimed in claim 1, wherein the silver halide emulsion layer and the light sensitive silver salt emulsion of the masking layer are optically sensitized to the same region of the spectrum.

3. A light sensitive material as claimed in claim 1, wherein the two silver halide emulsion layers are in contact with each other.

4. A light sensitive material as claimed in claim I, wherein the two silver halide emulsion layers are separated from each other by a thin intermediate layer.

5. A process for the production of a colored image combined with a colored masking image in a light sensitive material including (a) at least one light sensitive silver halide emulsion layer containing a color coupler which couples with the oxidation product ofaprimary aromatic amino developing agent upon photographic development to give a colored image and (b) a masking layer containing a spontaneously developable silver salt emulsion which is developable in a special photographic developing solution without exposure to actinic light and from about 1% to about 10% of the whole mixture of a light sensitive silver salt emulsion which is developable in said special developing solution only after exposure to actinic light, said spontaneously developable silver salt emulsion being of such lower light sensitivity than said light sensitive silver salt emulsion that upon exposure to the object to be reproduced only said light sensitive silver salt is affected, said special developer being a solution of a primary aromatic amino developing agent containing a solvent agent for said spontaneously developable silver salt and containing salts having the same anions as those of said light sensitive silver salt at most in such a quantity that the reduction of said spontaneously developable silver salt emulsion is not prevented, said masking layer v containing furthermore a color coupler as defined above and reduction nuclei said reduction nuclei being capable of catalysing the reduction of a silver salt emulsion to silver by a photographic developing solution without exposing said emulsions containing said reduction nuclei to actinic light, which process comprises exposing said light sensitive material to the object to be reproduced and developing said material in said special photographic developing solution.

' s I 6. A product as claimed in claim 1, wherein the silver salts of the masking layer are silver halides.

7. A light sensitive material as claimed in claim 6,

wherein the spontaneously developable silver salt emuls ion of the mashing layer contains silver chloride and the light sensitive silver salt emulsion of the masking layer contains silver bromide.

' References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,168,182 Wendt Aug. 1, 1939 2,193,931 Michaelis Mar. 19, 1940 2,352,014 Rott June 20, 1944 2,357,388 Duerr et al. Sept. 5, 1944 2,431,996 Duerr et al. Dec. 2, 1947 2,449,966 Hanson Sept. 21, 1948 2,490,751 Hanson Dec. 6, 1949 2,497,875 Fallesen Feb. 21, 1950 FOREIGN PATENTS Number Country Date 900,266 France Sept. 25, 1944 941,429 France July 19, 1948 503,752 Great Britain Apr. 11, 1939 634,169 Great Britain Mar. 15, 1950 

1. A LIGHT SENSITIVE MATERIAL FOR PRODUCING MASKED COLOR PHOTOGRAPHIC IMAGES WHICH COMPRISES (A) AT LEAST ONE LIGHT SENSITIVE SILVER HALIDE EMULSION LAYER CONTAINING A COLOR COUPLER WHICH COUPLES WITH THE OXIDATION PRODUCT OF A PRIMARY AROMATIC AMINO DEVELOPING AGENT UPON PHOTOGRAPHIC DEVELOPMENT TO GIVE A COLORED IMAGE AND (B) A MASKING LAYER CONTAINING A SPONTANEOUSLY DEVELOPABLE SILVER SALT EMULSION WHICH IS DEVELOPABLE IN A SPECIAL PHOTOGRAPHIC DEVELOPING SOLUTION WITHOUT EXPOSURE TO ACTINIC LIGHT AND FROM ABOUT 1% TO ABOUT 10% OF THE WHOLE MIXTURE OF A LIGHT SENSITIVE SILVER SALT EMULSION WHICH IS DEVELOPABLE IN SAID SPECIAL DEVELOPING SOLUTION ONLY AFTER EXPOSURE TO ACTINIC LIGHT, SAID SPONTANEOUSLY DEVELOPABLE SILVER SALT EMULSION BEING OF SUCH LOWER LIGHT SENSITIVITY THAN SAID LIGHT SENSITIVE SILVER SALT EMULSION THAT UPON EXPOSURE TO THE OBJECT TO BE REPRODUCE ONLY SAID LIGHT SENSITIVE SILVER SALT IS AFFECTED, SAID SPECIAL DEVELOPER BEING A SOLUTION OF A PRIMARY AROMATIC AMINO DEVELOPING AGENT CONTAINING A SOLVENT AGENT FOR SAID SPONTANEOUSLY DEVELOPABLE SILVER SALT AND CONTAINING SALTS HAVING THE SAME ANIONS AS THOSE OF SAID LIGHT SENSITIVE SILVER SALT AT MOST IN SUCH A QUANTITY THAT THE REDUCTION OF SAID SPONTANE OUSLY DEVELOPABLE SILVER SALT EMULSION IS NOT PREVENTED, SAID MASKING LAYER CONTAINING FURTHERMORE A COLOR COUPLER AS DEFINED ABOVE AND REDUCTION NUCLEI SAID REDUCTION NUCLEI BEING CAPABLE OF CATALYSING THE REDUCTION OF A SILVER SALT EMULSION TO SILVER BY A PHOTOGRAPHIC DEVELOPING SOLUTION WITHOT EXPOSING SAID EMULSIONS CONTAINING SAID REDUCTION NUCLEI TO ACTINIC LIGHT. 